Conduction bands of GaSb

Abstract

Room temperature measurements of free-carrier Faraday rotation have been made on four different single-crystal n-type tellurium-doped samples of GaSb which had been used previously in magnetoresistance measurements. From the combined results for each specimen, values have been calculated for the energy separation of the (000) and [Formula: see text] conduction band minima, ΔE, and the transverse effective-mass ratio of the [Formula: see text] electrons, m 1t /m. It is found that ΔE is a function of tellurium content. The value of ΔE at 4.2 °K for an intrinsic sample is hence found to be 0.078 eV. The values obtained for m 1t /m, the variation of ΔE with tellurium content (dΔE/dy), and the temperature coefficient of ΔE (dΔE/dT) depend upon the value of the scattering parameter s assumed in the analysis of the room-temperature data. It is shown that the correct value of s lies in the range 0.5 to 1.0 and this gives values for m 1t /m = 0.110 and dΔEdy = 0.50 eV/atomic % Te, while dΔE/dT probably lies in the range 0 to −2 × 10 −5 eV/°K.